One of my favorite types of training is interval training. Interval training is when you mix high intensity work with low intensity work. This method is hardly a secret technique anymore but is often overlooked as another great tool for the toolbox.

During high intensity effort, our bodies use energy stored in our muscles. During these short bursts of activity lactic acid is produced. This lactic acid in turn creates a burning sensation in our muscles letting our bodies know we are reaching failure. During this period our muscles are also getting starved of oxygen. When we switch to low intensity tasks our heart and lungs work together to recover oxygen and remove excess lactic acid from our muscles. Our bodies adapt from the stress of the intense interval portion by building new capillaries and in turn improving oxygen delivery. This improves our muscle’s tolerance to the upsurge of lactate and also strengthens our cardiovascular system resulting in improved performance.

In the study Two weeks of high-intensity aerobic interval training increases the capacity for fat oxidation during exercise in women, published in the Journal of Applied Physiology, Dr. Jason Talanian found that after just two weeks of interval training, 75% of participants doubled their endurance before getting exhausted. Further, that bursts of high intensity exercise not only improve cardiovascular fitness but also the body’s ability to burn fat faster. The amount of fat burned in an hour of continuous moderate cycling increased by 36% and cardiovascular fitness increased by 13%. Although this study was conducted with women the study provides precedent to suggest that aerobic and mitochondrial enzyme adaptation in well-trained individuals would be similar across both sexes.

Further studies such as Mark Rakobowchuk’s Sprint interval and traditional endurance training induce similar improvements in peripheral arterial stiffness and flow-mediated dilation in healthy humans suggest that short bursts of high intensity sprints can improve the function and structure of our blood vessels, in particular arteries that deliver blood to our muscles and heart. The research compared individuals who completed interval training using 30-second “all-out” sprints three days a week to a group who completed between 40 and 60 minutes of moderate-intensity cycling five days a week. The results showed that six weeks of intense sprint interval exercise training improved the structure and function of arteries in a comparable manner to that of extended endurance training, making interval training a “time-efficient strategy to elicit improvements in peripheral vascular structure”.

For runners with limited time to train (like myself), interval training isn’t just an economical way to increase your aerobic threshold …but running speed as well. Intuitively, we can train at higher speeds for shorter distances so interval training gives us the opportunity to test speeds outside of our comfort zone. However, because we are training in and out of anaerobic and aerobic conditions, one should also approach this type of training with caution and make sure that they are in a condition to put this type of stress on their body. Serious interval training is not for anyone that remotely thinks they might have biological system deficiencies …but in healthy individuals it can be a great way to maximize results in a minimum amount of time.

I know it is a cliché: happiness is a choice; but it’s a cliché backed by empirical evidence. In practice though, it isn’t always that easy. Speaking from my own experience it takes a lot of work to engage in the type of self-awareness needed to alter one’s mood by simply switching focus. But hear me out and you might be whistling a happier tune by the time you finish reading this…

While researching positive psychology I have seen the studies that point to a genetic predisposition to happiness. Some researchers in psychology argue that we inherit our ability to be happy and that the level to which we are able to derive satisfaction in life is significantly influenced by our genetic make-up. However, in the study Long-Running German Panel Survey Shows That Personal and Economic Choices, Not Just Genes, Matter for Happiness researchers observed 60,000 Germans over the span of 25 years, and found that levels of individual happiness actually correlated stronger with setting goals and personal choice and less on genetic factors.

In the long-term, those who value family and personal relationships seem to be happier than those who are focused on material success and/or career advancement, which strengthens the argument about happiness as a choice because personal relationships are an area where we have much better control over external outcomes. For example, we can decide to be a good friend (or not), but we cannot decide to force our company to give us a promotion.

So how is happiness affected based on personal choice? There are many easy ways we can influence our own behavior that will help improve your mood. One way we can increase happiness is by making a conscious effort to focus on the positive attributes of any given situation. Deciding what to focus on in any given circumstance is a personal choice, and one of the most straightforward ways to increase happiness. There are more subtle ways as well… For instance, making an effort to keep a mild and friendly pitch when we talk has shown to increase mood. In the study Speech Pitch Frequency as an Emotional State Indicator, evidence suggests that the pitch and tone of our voice reflect and affect our emotional state. Gentler tones will also maintain low stress levels in the people around us. Another example is, accordingly to the brief report Keep Smiling: Enduring Effect of Facial Expressions and Postures on Emotional Experience and Memory, the simple act of choosing to smile. Simply making an effort to smile more has been shown to have a positive effect on our well-being in numerous ways and happiness is one of them.

In short, current scientific findings are challenging that happiness is somehow outside of our control. Simply being cognizant that you have power over your emotional state, and coming to the realization that you can actively decide how you are effected by certain life events, can help increase your overall happiness in very profound ways. If you have any tactics that work for you, please share them in the comments below.

Nat Turner, the co-founder of Invite Media, is a self-made multimillionaire who sold his start-up to Google for $70 million in his early 20s. In an interview with CNN Nat Turner shares some valuable information to inspiring entrepreneurs and gives his opinion about why young entrepreneurs might have a leg up on their more established counterparts.

Takeaways from Nat Turner’s interview, if you do not feel like watching the video below, are:

The best time to start a new venture is when nobody else is (in other words, recessions are actually a great time to start a company)

Luck seems to follow those that work extremely hard

Therefore, make sure you work harder and smarter than your competitors

Young entrepreneurs often approach problems differently than older entrepreneurs which can lead to unique solutions

Another interesting observation is that Nat cut his entrepreneurial teeth at a young age (selling reptiles out of his home). This seems to be a common theme among successful entrepreneurs (so a quick digression for parents with budding entrepreneurs… make sure to support and encourage your children’s aspirations!).

Isaac Newton once famously remarked, “…if I have seen a little further it is by standing on the shoulders of giants.” The statement has been generally accepted to mean that worthy pursuits are only advanced through the progress created by continuing the work of great minds of the past.

David Christian is a Professor of History at Macquarie University in Sydney, Australia and is currently collaborating on a venture called the Big History Project with Bill Gates. He gave a talk about the Project at a recent TED conference. Within Dr. Christian’s presentation there was a topic that might be of particular interest to performance psychologists and researchers, which is the concept of “collective Learning”. Dr. Christian credits collective learning as being the catalyst that has allowed humans to flourish, but he also warns that this power might not be completely in our control – highlighting our species complexity and fragility through historical and current events.

Much like DNA is the system that stores biological information, collective learning is a global system that stores our vast body of knowledge. It began to exist the moment human language was created and was immensely empowered further with the advent of the Internet. Collective learning outlasts the knowledge of any one individual and evolves with the passing of each generation. Our ability to share and improve information is what makes humans different than every other known species. It has allowed humans to improve performance and achievement with each passing generation. Honoring the idea of collective learning one is able to learn for others and contribute to the greater good.

Christopher McDougall, author of Born to Run gave his opinion about how people’s desire to run might have evolved at a recent TED conference. Although Christopher McDougall covered a variety of topics on running during his TED presentation (including a heartwarming story about the marathoner Derartu Tulu, who was ready to retire from professional running, but instead beat Paula Radcliffe in the 2009 New York Marathon), it is his argument that people don’t benefit from running shoes that has caused a lot of buzz in the running community lately. McDougall argues that the natural human foot structure is already fit to run without protection because its design has been perfected through years of evolution.

Christopher McDougall’s position is backed up by recent research out of Harvard. In a study published in Nature, Foot strike patterns and collision forces in habitually barefoot versus shod runners, evidence indicated running barefoot might have lower shock/impact on our overall leg structure. In the study, barefoot runners experienced shock of only 0.5 to 0.7 times their human body weight. The impact was two to three times more for runners who wore shoes. The main difference was observed on foot landing. Shod runners landed on the heel of their foot while barefoot runners landed flatfooted or on the ball of their foot. Running barefoot, scientists suggest in the study, causes more bend in the foot’s spring and calls for more foot and calf muscle participation which causes less shock on the rest of the body making for more comfortable running strides.

What is your opinion about running without shoes? Let us know in the comments section below.